A consumption log is useful only if “used” has a consistent meaning. Product delivered to a storeroom, issued to a department and actually consumed are three different events. Decide which one the log measures before comparing weeks or locations.
For a simple stock-based log, use opening usable stock plus receipts minus closing usable stock, with adjustments recorded separately. Count the same storage locations and use the same unit each period.
Choose units that staff can maintain
Track litres, kilograms or clearly defined containers as appropriate to the product and record. Do not add unlike units together or assume every container is full. Agree a practical method for recording partial stock without unsafe handling or unnecessary transfers.
A hypothetical example illustrates the arithmetic: 12 litres opening stock plus 20 litres received minus 18 litres closing stock gives 14 litres leaving the measured stock boundary. That figure still needs context before it can be called actual cleaning consumption.
Record adjustments and workload
Show transfers, damaged stock, returns and known losses separately. If a container moves to another storeroom, it should not look like a sudden increase in product use.
Add a relevant workload measure such as racks processed, operating days or tasks completed. Choose a measure that makes sense for the product. Guest count may not explain every difference in warewashing or surface-cleaning demand.
Investigate exceptions carefully
A change can reflect workload, stock-count errors, a different product format or a process issue. Check the record before assuming staff are overusing chemicals. Changes to dispensing settings require the appropriate provider, not a spreadsheet-driven guess.
Keep formulas visible and protect the original period entries from casual overwriting. Corrections should be dated and explained so the history remains understandable.
Use the cost-per-rack guide for a warewashing calculation and the reorder-point guide for stock planning. A good log provides questions worth investigating; it does not diagnose a chemical or equipment problem on its own.